(BQ) Part 1 book Skeletal radiology the bare bones presents the following contents: Approach to trauma, trauma in adults - Upper extremity, axial skeleton, lower extremity, trauma in children, imaging of fracture treatment and healing, approach to bone lesions, malignant and aggressive tumors, benign lesions, metastatic tumors.
THIRD EDITION SKELETAL RADIOLOGY The Bare Bones FELIX S CHEW, M.D., Ed.M., M.B.A Professor of Radiology Director of Musculoskeletal Radiology Vice-Chairman for Radiology Informatics Department of Radiology University of Washington Seattle, Washington WITH CONTRIBUTIONS FROM LIEM T BUI-MANSFIELD, M.D CATHERINE C ROBERTS, M.D MICHAEL L RICHARDSON, M.D Chew_FM.indd i 1/21/2010 12:37:10 PM Acquisitions Editor: Charles W Mitchell Product Manager: Ryan Shaw Vendor Manager: Alicia Jackson Senior Manufacturing Manager: Benjamin Rivera Senior Marketing Manager: Angela Panetta Design Coordinator: Teresa Mallon Production Service: SPi Technologies Copyright © 2010 Text and Illustrations by Felix S Chew, M.D Copyright © 2010 Design and Publication Rights by Lippincott Williams & Wilkins © 2010 by LIPPINCOTT WILLIAMS & WILKINS, a WOLTERS KLUWER business Two Commerce Square 2001 Market Street Philadelphia, PA 19103 USA LWW.com All rights reserved This book is protected by copyright No part of this book may be reproduced in any form by any means, including photocopying, or utilized by any information storage and retrieval system without written permission from the copyright owner, except for brief quotations embodied in critical articles and reviews Materials appearing in this book prepared by individuals as part of their official duties as U.S government employees are not covered by the above-mentioned copyright Printed in China Library of Congress Cataloging-in-Publication Data Chew, Felix S Skeletal radiology : the bare bones / Felix S Chew ; with contributions from Liem T Bui-Mansfield, Catherine C Roberts, Michael L Richardson — 3rd ed p ; cm Includes bibliographical references and index ISBN 978-1-60831-706-6 (alk paper) Human skeleton—Radiography Bones—Diseases—Diagnosis Bones—Imaging I Title [DNLM: Bone and Bones—radiography Bone Diseases—radiography Fractures, Bone—radiography WE 200 C526s 2010] RC930.5.C48 2010 616.7'107572—dc22 2009050533 Care has been taken to confirm the accuracy of the information presented and to describe generally accepted practices However, the authors, editors, and publisher are not responsible for errors or omissions or for any consequences from application of the information in this book and make no warranty, expressed or implied, with respect to the currency, completeness, or accuracy of the contents of the publication Application of the information in a particular situation remains the professional responsibility of the practitioner The authors, editors, and publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accordance with current recommendations and practice at the time of publication However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any change in indications and dosage and for added warnings and precautions This is particularly important when the recommended agent is a new or infrequently employed drug Some drugs and medical devices presented in the publication have Food and Drug Administration (FDA) clearance for limited use in restricted research settings It is the responsibility of the health care provider to ascertain the FDA status of each drug or device planned for use in their clinical practice To purchase additional copies of this book, call our customer service department at (800) 638–3030 or fax orders to (301) 223–2320 International customers should call (301) 223–2300 Visit Lippincott Williams & Wilkins on the Internet: at LWW.com Lippincott Williams & Wilkins customer service representatives are available from 8:30 am to pm, EST 10 Chew_FM.indd ii 1/21/2010 12:37:10 PM To my family, without whom nothing would be possible, worthwhile, or meaningful Chew_FM.indd iii 1/21/2010 12:37:10 PM CHAPTER FOREWORD 45 The initial publication of Felix S Chew’s Skeletal Radiology: The Bare Bones filled a long-standing need for a concise, introductory primer to the imaging of musculoskeletal diseases For this, the third edition, Dr Chew has the contributions of three outstanding musculoskeletal radiologists; Drs Liem Bui-Mansfield, Catherine Roberts, and Michael Richardson Together these authors have thoroughly updated the information available in their new work including considerably more magnetic resonance imaging and CT Most of the older radiographic images have been replaced with newer digital radiographic images The text has been revised as necessary, and the sources and readings have been updated That said, Dr Chew’s basic approach has been maintained throughout; the emphasis remains on explanations and descriptions that are to be understood and applied rather than the now common presentation of lists of facts that tend to be memorized and forgotten Medical school curricula not often include a serious study of afflictions of the bones and joints Even the most common conditions; trauma, osteoporosis, bone metastases, and degenerative joint disease receive scant attention As a result, most first year residents come to radiology with a limited knowledge of the musculoskeletal system and its diseases Therefore, the neophyte resident’s introduction to musculoskeletal radiology can be daunting With this limited background, trainees have thrust upon them a vast array of unfamiliar disease processes, a perplexing variety of normal variants, and the complex radiologic anatomy of several different body regions What are these new radiology residents to do? Fortunately, there’s The Bare Bones Radiology residents can turn to this excellent text to acquire a firm foundation for musculoskeletal imaging Dr Chew provides the uninitiated with a working knowledge of skeletal disease and an awareness of the role and value of imaging in the discovery, analysis, and confirmation of the various skeletal abnormalities In stripping skeletal radiology to its essentials, Dr Chew and his coauthors have actually left considerable flesh on the bones The information in The Bare Bones is hardly bare or even spare All the essentials are covered All of the critical aspects of the most common skeletal diseases are described and illustrated The authors synthesize the current knowledge regarding the clinical, pathologic, and physiologic features of each disease, and then outline the proper approach to the interpretation of radiographs, computed tomography, magnetic resonance imaging, and skeletal scintigrams The important features of each disorder are demonstrated with exceptional illustrations, augmented, as necessary, by excellent diagrams, and appropriately summarized in tables This masterful approach is consistently applied with superb results The book is divided into four parts The six chapters of Part I are devoted to trauma, properly reflecting the frequency with which skeletal injuries are encountered and the overriding importance of imaging in the diagnosis and management of fractures and dislocations The first chapter gives an excellent background to the clinical and biomechanical considerations The next three chapters address injuries of the upper extremity; spine, thoracic cage, and pelvis; and lower extremity, respectively Chapter describes the distinctive nature of skeletal trauma in children, and Chapter describes imaging of fracture treatment and healing Part II begins with a discussion of the clinical features and imaging approach to lesions of the bone These lesions are then enumerated individually and described in separate chapters on malignant and benign lesions The final chapter is justifiably devoted to the frequently encountered clinical problem of metastatic disease to the skeleton, and emphasizes the primary role of imaging techniques in detection and management Part III covers joint disease, beginning with a description of basic clinical and pathologic features An overall approach to the radiology of arthritis is presented, followed by chapters on inflammatory arthritis and noninflammatory joint disease In separate chapters, Part IV describes developmental and congenital conditions; metabolic, endocrine, and nutritional conditions; and infections of the bones, joints, and soft tissues There follows a chapter on postsurgical imaging that includes a thorough discussion of the use of imaging in joint replacement, a topic of particular interest to Dr Chew It is all here I recommend this book to all residents in diagnostic radiology, indeed to all students of skeletal disease Medical students with an interest in diagnostic radiology, orthopedic surgery, or rheumatology would certainly benefit from its contents Experienced radiologists will find it a great refresher and undoubtedly gain new insights into musculoskeletal diseases and pick up several useful pointers on musculoskeletal imaging along the way Teachers of skeletal radiology will discover that the approaches developed and the excellent tables and figures can be of considerable value in preparing their own presentations Dr Chew’s first two editions of The Bare Bones were outstanding This third edition is even better If you would like to improve your musculoskeletal imaging skills – read on! Lee F Rogers, M.D Clinical Professor Department of Radiology University of Arizona Tucson, AZ iv Chew_FM.indd iv 1/21/2010 12:37:10 PM CHAPTER PREFACE 45 he ranges of pathology and individual variation in the skeleton are too vast for sheer memorization and pattern recognition One is better able to appreciate abnormalities on images when one understands how the radiologic findings mirror the underlying conditions For trauma, this requires some familiarity with biomechanics; for oncology, an appreciation of radiologic-pathologic correlation; and for developmental conditions, an understanding of skeletal growth, maturation, and functional adaptation In the 20 years since the publication of the first edition of The Bare Bones, the wider application and further refinement of MRI and CT have continued to reduce the role of radiography in musculoskeletal imaging Inferential diagnosis on the basis of radiologic signs has lost ground to the deliberate demonstration of specific anatomic and pathophysiologic features of disease The choice and specific performance of examinations have become particularly dependent on clinical context It is no longer sufficient to react to an image with a list of differential diagnoses; rather, one must consider the clinically relevant possibilities and devise strategies for distinguishing among them with certainty Skeletal Radiology: The Bare Bones, Third Edition, is a single unified textbook that teaches general principles of skeletal radiology T that are applicable regardless of imaging modality Organized into four parts, this book presents the core knowledge base in musculoskeletal imaging necessary for a radiology resident Part I covers musculoskeletal trauma, beginning with an approach to trauma and concluding with separate chapters describing trauma to the upper and lower extremities in adults, trauma to the adult spine, trauma in children, and fracture healing and treatment Part II covers tumors and tumorlike lesions, beginning with an approach to bone lesions and concluding with separate chapters on malignant and aggressive tumors, benign lesions, and metastatic tumors Part III covers joint disease, beginning with an approach to joint disease and concluding with separate chapters on inflammatory arthritis and noninflammatory joint disease Part IV covers miscellaneous topics, including chapters on developmental and congenital conditions, metabolic, endocrine, and nutritional conditions, infection and marrow disease, and postsurgical musculoskeletal imaging The final chapter covers interventional procedures in musculoskeletal radiology Although this book is intended specifically for radiologists and radiologists-in-training, it is also suitable for practitioners and trainees in all fields who deal with the diagnosis and management of musculoskeletal disease v Chew_FM.indd v 1/21/2010 12:37:10 PM CHAPTER ACKNOWLED GMENTS 45 he images in this textbook were selected from the teaching files and clinical case material at Upstate Medical Center in Syracuse, New York; the Massachusetts General Hospital in Boston, Massachusetts; Wake Forest University Baptist Medical Center in Winston-Salem, North Carolina; Keller Army Community Hospital in West Point, New York; the Cleveland Clinic Foundation in Cleveland, Ohio; the University of Washington Medical Center in Seattle, Washington; Harborview Medical Center in Seattle, Washington; the Mayo Clinic Arizona in Scottsdale, Arizona; and Brooke Army Medical Center, San Antonio, Texas Friends and colleagues who have graciously provided additional case material include Drs Carol Boles, William Enneking, Joel Gross, Martin T Gunn, Heather Hardie, Terry Hudson, Linda Hughes, John Hunter, Mitchell Kline, Wendy Jones, Susan Kattapuram, Michelle Kraut, Susan Leffler, Leon Lenchik, Mark Levinsohn, Gwilym Lodwick, Catherine Maldjian, Liem Bui-Mansfield, Henry Mankin, Kevin McEnery, Michael Mulligan, Robert Novelline, William Palmer, Michael Richardson, Catherine Roberts, Lee Rogers, Daniel Rosenthal, Dempsey Springfield, and others whom I may have unintentionally overlooked at the moment of this writing The line illustrations were drawn by Crisianee Berry —Felix S Chew vi Chew_FM.indd vi 1/21/2010 12:37:11 PM ABBREVIATIONS AND ACRONYMS ACL AIDS ALPSA ANA AP BHAGL BMD C1, C2, C3, etc CMC joint CPPD CT DDH DEXA DIP joint DISH DISI DPA DXA FS Gd GLAD GRE HAGL HIV HLA HU IM rod IP joint K-wire anterior cruciate ligament acquired immunodeficiency syndrome anterior labrum periosteal sleeve avulsion antinuclear antibodies anteroposterior bony humeral avulsion of the inferior glenohumeral ligament bone mineral density, bone mineral densitometry first cervical vertebra (atlas), second cervical vertebra (axis), etc carpometacarpal joint calcium pyrophosphate dihydrate computed tomography developmental dysplasia of the hip dual energy x-ray absorptiometry distal interphalangeal joint diffuse idiopathic skeletal hyperostosis dorsal intercalated segment instability (dorsiflexion instability) dual photon absorptiometry dual x-ray absorptiometry fat suppression gadolinium glenolabral articular disruption gradient recalled echo humeral avulsion of the inferior glenohumeral ligament human immunodeficiency virus human leukocyte antigen Hounsfield unit (unit of x-ray attenuation on a CT scan) intramedullary rod interphalangeal joint Kirschner wire L1, L2, L3, etc LCL MCL MCP joint MFH MR MRI MTP joint OCD ORIF PA PCL PET PIP joint PMNs PVNS QCT RF S1, S2, S3, etc SCFE SI joint SLAP tear SLE STIR T1, T2, T3, etc TFCC THR TKR TMT joint VISI WBC first lumbar vertebra, second lumbar vertebra, etc lateral collateral ligament (of the knee) medial collateral ligament (of the knee) metacarpophalangeal joint malignant fibrous histiocytoma magnetic resonance magnetic resonance imaging metatarsophalangeal joint osteochondral defect, osteochondritis dissecans open reduction internal fixation posteroanterior posterior cruciate ligament positron emission tomography proximal interphalangeal joint polymorphonuclear leukocytes pigmented villonodular synovitis quantitative computed tomography rheumatoid factor first sacral vertebra, second sacral vertebra, etc slipped capital femoral epiphysis sacroiliac joint superior labrum anterior to posterior tear systemic lupus erythematosus short tau inversion recovery first thoracic vertebra, second thoracic vertebra, etc triangular fibrocartilage complex total hip replacement total knee replacement tarsometararsal joint volar intercalated segment instability (volar flexion instability) white blood cell vii Chew_FM.indd vii 1/21/2010 12:37:11 PM CHAPTER FIGURE CREDITS 45 FIGURE 8.27 A–C: FIGURE 16.1 A, B: From Ramsdell MG, Chew FS, Keel SB Myxoid liposarcoma of the thigh AJR 1998;170:1242 From Chew FS, Schulze ES, Mattia AR Osteomyelitis AJR 1994;162:942 FIGURE 17.27 A, B: From Chew FS, Ramsdell MG, Keel SB Metallosis after total knee replacement AJR 1998;170:1556 FIGURES 1.1–8.26, FIGURES 8.28–15.41, FIGURES 16.2–17.26, and FIGURES 17.28–17.51: Used with permission from the following sources: Chew FS Skeletal Radiology: The Bare Bones Rockville, MD: Aspen Publishers; 1989; Chew FS Skeletal Radiology: The Bare Bones Teaching Collection St Paul, MN: Image PSL; 1991; Chew FS Skeletal Radiology: The Bare Bones 2nd Ed., Baltimore, MD: Williams & Wilkins; 1997; Chew FS Skeletal Radiology Interactive Baltimore, MD: Williams & Wilkins; 1998; Chew FS, Maldjian C, Leffler SG Musculoskeletal Imaging: A Teaching File Philadelphia, PA: Lippincott Williams & Wilkins; 1999; Chew FS, Kline MJ, Whitman GJ, eds iRAD: Interactive Radiology Review and Assessment Philadelphia, PA: Lippincott Williams & Wilkins; 2000; Chew FS Skeletal Radiology Interactive 2.0 Winston-Salem, NC: Bubbasoft of North Carolina; 2002; Chew FS Skeletal Radiology Interactive 3.0, Bainbridge Island, WA: Northwest Bubbasoft; 2009; Chew FS, Maldjian C Broken Bones: The X-Ray Atlas of Fractures Seattle, WA: BareBonesBooks.com; 2009 viii Chew_FM.indd viii 1/21/2010 12:37:11 PM CONTENTS Foreword iv Preface v Acknowledgments vi Abbreviations and Acronyms Figure Credits viii PA R T PA R T 10 PA R T 11 12 13 PA R T 14 15 16 17 Index vii I: Trauma Approach to Trauma Trauma in Adults: Upper Extremity 17 Trauma in Adults: Axial Skeleton 42 Trauma in Adults: Lower Extremity 63 Trauma in Children 87 Imaging of Fracture Treatment and Healing 106 II: Tumors Approach to Bone Lesions 126 Malignant and Aggressive Tumors 140 Benign Lesions 158 Metastatic Tumors 181 III: Joint Disease Approach to Joint Disease 196 Inflammatory Arthritis 207 Noninflammatory Joint Disease 225 IV: Miscellaneous Topics Developmental and Congenital Conditions 250 Metabolic and Systemic Conditions 276 Infection and Marrow Disease 297 Postsurgical Imaging 315 335 ix Chew_FM.indd ix 1/21/2010 12:37:11 PM Chew_FM.indd x 1/21/2010 12:37:11 PM 180 Part II • Tumors Schmidt H, Freyschmidt J Köhler/Zimmer Borderlands of Normal and Early Pathologic Findings in Skeletal Radiography 4th Ed New York, NY: Thieme; 1993 Stull MA, Kransdorf MJ, Devaney KO Langerhans’ cell histiocytosis of bone Radiographics 1992;12:801–823 Sundaram M, Wang LH, Rotman M, et al Florid reactive periostitis and bizarre parosteal osteochondromatous proliferation: Pre-biopsy Chew_Chap09.indd 180 imaging evaluation, treatment and outcome Skeletal Radiol 2001;30: 192–198 Unni KK Dahlin’s bone tumors General Aspects and Data on 11,087 Cases 5th Ed Philadelphia, PA: Lippincott–Raven; 1996 Yuen M, Friedman L, Orr W, et al Proliferative periosteal processes of phalanges: A unitary hypothesis Skeletal Radiol 1992;21:301 4/29/2010 6:33:13 PM CHAPTER 10 Incidence Tumor Spread Radiologic Appearance Screening for Metastases T Metastatic Tumors Hematologic Malignancies Involving the Bone Secondarily Leukemia Hodgkin Lymphoma Non-Hodgkin Lymphoma his chapter describes the radiology of tumors that are metastatic to bone or soft tissue INCIDENCE More than 95% of adult patients with malignant disease involving bone have metastases rather than myeloma or primary bone sarcomas The prevalence of bone involvement in autopsy series of cancer patients ranges from 3% to 85%, depending on the site of origin and the thoroughness of the postmortem search With improving cancer treatments and longer patient survival, more and more cancer patients will have skeletal involvement by the end of their clinical course Most skeletal metastases occur in middle-aged and elderly patients with primary cancers of the prostate, breast, lung, or kidney In men, prostate malignancies account for 60% of patients with skeletal metastases; in women, breast malignancies account for 70% (Table 10.1) In children with osseous metastases, neuroblastoma is the most common primary lesion (Table 10.2) TAB LE 10.1 Frequency of Primary Sites Among Adults with Skeletal Metastases Primary Site Frequency (%) Women Breast Lung Kidney Uterus Thyroid Others/unknown Total 70 4 13 100 Men Prostate Lung Kidney GI tract Others/unknown Total 60 14 17 100 Pathologic Fracture Soft-Tissue Metastases Percutaneous Needle Biopsy Treatment Radiotherapy Changes The relative incidence of primary tumors that are likely to metastasize to the bone may be affected in the future by the rising incidence of lung cancer among women (due to smoking), the decrease in the proportion of advanced breast cancers (due to screening mammography), and the increasing incidence of breast and prostate cancers overall (due to an aging population) Most skeletal metastases are subclinical and asymptomatic When symptomatic, they present as bone pain or pathologic fractures Bone pain ranges in severity from minimal to extreme and intolerable, but skeletal metastases are themselves rarely a cause of death In the radiologic evaluation of metastatic bone tumors, less emphasis is placed on complete anatomic delineation of individual lesions and more on discovering sites of disease and planning and following the course of palliative therapy Sometimes, a skeletal metastasis is the initial presentation of malignant disease in a patient whose primary site is asymptomatic or minimally symptomatic Occult primary tumors that present with bone metastases are usually kidney, lung, and gastrointestinal tract lesions Only in select cases does locating the primary tumor benefit the patient, because in most instances, the prognosis has already become unalterable by metastatic dissemination In most cases, the primary tumor is never located, even at autopsy Biopsy of the skeletal metastasis in these circumstances often shows adenocarcinoma without organ-specific features TAB LE 10.2 Primary Tumors in Children That May Metastasize to Bone Neuroblastoma Leukemia Lymphoma Ewing sarcoma Osteosarcoma Malignant soft-tissue sarcomas Retinoblastoma Embryonal rhabdomyosarcoma Medulloblastoma Wilms tumor 181 Chew_Chap10.indd 181 1/18/2010 10:58:28 AM 182 Part II • Tumors TUMOR SPREAD Tumor cells gain access to the skeleton by (a) hematogenous spread through the arterial circulation, (b) retrograde venous flow, and (c) direct extension The portions of the skeleton that contain red marrow have a rich vascular supply, and tumor emboli frequently lodge within the sinusoidal channels found there Tumor spread through retrograde venous flow occurs in the valveless vertebral plexus of Batson This venous plexus interconnects the spine, the ribs, and the pelvis, providing access to the axial skeleton Blood flow through the plexus may be transiently reversed by increased intra-abdominal pressure caused by activities such as coughing Direct extension is much less frequent than hematogenous spread; when it occurs, it is usually an extension of an intrathoracic tumor to the chest wall, an intrapelvic tumor to the pelvic wall, or a retroperitoneal process to the lumbar spine For practical purposes, lymphatic spread of tumor to the bone does not occur Metastases in the cancellous bone of the axial skeleton and in the cancellous metaphyseal bone of the proximal femur and proximal humerus account for nearly 90% of lesions, a distribution that is related to hematogenous spread Metastases to the spinal column usually involve the vertebral body rather than the posterior elements They are more common in the lumbar region than the thoracic region and least common in the cervical region Metastases are distinctly uncommon distal to the knees or elbows Approximately 90% of patients with bone metastases have multifocal involvement Skeletal metastases are common around joints, especially the hips, shoulders, knees, and intervertebral disks Periarticular metastases with subchondral, intra-articular, or synovial extension may have a clinical presentation that simulates inflammatory arthritis Lesions in the hands or feet are relatively rare and usually come from primary lung cancers The intervertebral disk is a relative barrier to the spread of tumor, so that the usual pattern of vertebral metastatic involvement is vertebral destruction with preservation of the disk, even when multiple contiguous vertebral levels have tumor It is very unusual for the disk to be involved by tumor Coexistent degenerative disk disease is frequent and may be caused or exacerbated secondarily by the presence of tumor In the subchondral region of the vertebral body, a metastasis may interfere with the nutrition of the disk or weaken the end plate so that the disk material herniates through The former process produces degenerative disk disease, and the latter produces a Schmorl node TAB LE 10.3 Typical Radiologic Appearances of Metastases from Specific Primary Tumors Primary Tumor Appearance on Site Radiographs Appearance on Bone Scan Breast Lytic, mixed, or blastic Prostate Blastic, occasionally mixed or lytic Lytic, mixed, occasionally blastic Lytic, expansile or blow-out Lytic, expansile or blow-out Increased isotope uptake Increased isotope uptake Increased isotope uptake Often decreased isotope uptake Often decreased or normal isotope uptake Lung Kidney Thyroid stroma, osteoprogenitor cells form the bone under the influence of osteoinductive humoral factors secreted by the tumor Metastases from prostatic carcinoma produce a fibrous stroma and form the bone in this way; metastases from breast and lung carcinomas not In reactive bone formation, immature woven bone forms at the same time that bone destruction occurs Proposed mechanisms for reactive bone include a mechanical response to weakening of the bone by the growing metastasis, an attempt by the bone to contain the lesion, or perhaps an uncoupling of the humoral factors that normally control the bone formation and resorption Lytic lesions correspond to destruction and replacement of the bone by nonmineralized tumor, without appreciable bone formation The pattern of destruction may be geographic, permeated, or moth-eaten, and although there is a rough correspondence to increasing biologic aggressiveness, all patterns may be present in the same patient when extensive disease is present (Figs 10.1 and 10.2) Because 30% to 50% of bone mineralization must be lost before a lesion becomes visible on the plain film, widespread lytic metastases may be inapparent on radiographs Blastic lesions correspond to RADIOLOGIC APPEARANCE The appearance of a bone metastasis on radiographs reflects the balance of bone destruction and bone formation (Table 10.3) Metastatic tumors secrete osteoclast-stimulating factors; the osteoclasts excavate a defect in the bone where the metastasis establishes itself The osteoclasts are not part of the tumor mass but can be found at the periphery, sometimes separated by the fibrous tissue Growth of the tumor is preceded by osteoclastic bone resorption When bony trabeculae have been completely engulfed, tumor can destroy the bone directly by elaborating enzymes Osteoclast proliferation and osteoclastic bone resorption occur in all bone metastases, regardless of whether they also form the bone Bone formation may occur as stromal bone formation or as reactive bone formation In those tumors associated with an acellular fibrous Chew_Chap10.indd 182 FIGURE 10.1 Hypervascular renal cell carcinoma metastasis (arrow) destroying the sternum and proximal left clavicle with large soft-tissue mass on axial CT 1/18/2010 10:58:28 AM Chapter 10 • Metastatic Tumors 183 FIGURE 10.2 Lytic metastases from breast carcinoma A: Huge destructive lesion (arrow) in the ilium B: Lytic lesion (arrow) in the anterior two thirds of the L3 vertebral body bone formation in or around tumor implants through reactive bone proliferation or ossification in fibrous stroma Reactive apposition of the new bone on cancellous bone surfaces results in a dense, blastic appearance Proliferation of new endosteal bone is seen as endosteal thickening or irregular densities projected over the marrow cavity Deposition of periosteal new bone causes cortical thick- ening or layers of periosteal new bone Metastatic lesions usually not stimulate periosteal new bone, and when they do, the periosteal bone tends to be scanty The pattern of reactive bone proliferation generally reflects the tumor’s growth rate, with highly anaplastic, fast-growing tumors and marrow element malignancies (myeloma and leukemia) provoking no radiographically appreciable reactive FIGURE 10.3 Blastic metastases from breast carcinoma in the intertrochanteric region of the femur A: A homogeneously dense blastic lesion (arrow) with poorly defined margins B: Bone scan shows increased radionuclide accumulation in the lesion (arrow) and in the ipsilateral acetabulum Chew_Chap10.indd 183 1/18/2010 10:58:28 AM 184 Part II • Tumors FIGURE 10.4 Diffuse blastic metastases from prostate carcinoma throughout the pelvis and proximal femurs bone Blastic metastases tend to have a dense homogeneous appearance with margins that fade imperceptibly into the normal bone (Figs 10.3 and 10.4) Mixed lesions contain both lytic and blastic areas, reflecting bone destruction and bone formation in different portions of the same lesion (Fig 10.5) In fact, both processes occur simultaneously in virtually all metastases FIGURE 10.6 Bone scan shows multiple metastases from breast carcinoma FIGURE 10.5 Metastasis from breast cancer detected by PET/CT A: CT scan shows mixed lytic-sclerotic lesion (arrow) in the left iliac wing, adjacent to the sacroiliac joint B: Fused FDG-PET/CT image shows high standard uptake value (arrow) in the lesion CT-guided biopsy confirmed the diagnosis Chew_Chap10.indd 184 Radionuclide bone scan is more sensitive than radiographs for detecting metastases but has lower specificity Radionuclide bone scanning agents such as technetium-99m methylene diphosphonate accumulate in new reactive or stromal bone (Fig 10.6; see Fig 10.3) The metastasis itself may not accumulate the tracer unless the primary lesion forms the bone or cartilage Most lytic lesions, as well as all blastic and mixed lesions, have enough new bone formation to appear as areas of intense uptake on scans If the activity in the reactive and stromal bones is equal to that of a normal bone or if the metastasis is in the marrow space but does not affect the bone, the scan is falsely negative If a bone is destroyed and replaced by tumor without provoking detectable reactive bone, an area of decreased uptake may result Anaplastic, purely lytic lesions tend to have decreased uptake A “superscan,” that is, diffuse increased radionuclide accumulation throughout the entire skeleton, can indicate diffuse osseous metastatic disease Positron emission tomography (PET) using 18-fluorodeoxyglucose (18F-FDG), a radioactive-labeled glucose analog that permits imaging based on the metabolic rate, has considerable utility in oncologic imaging With regard to screening for skeletal metastases, compared with the radionuclide bone scan, PET with 18F-FDG appears to have a higher sensitivity and higher specificity for detection of osteolytic metastases Osteoblastic metastases and osteosarcoma metastases appear to have lower metabolic rates than osteolytic metastases, and the radionuclide bone scan appears better than PET in these circumstances PET/CT has the additional advantage of combining the sensitivity and specificity of PET with the spatial resolution of CT (see Fig 10.5) 1/18/2010 10:58:30 AM Chapter 10 • Metastatic Tumors 185 FIGURE 10.8 Marrow space metastasis in the left femur (arrow) from lung cancer demonstrated by CT The bone scan was negative in the region of this lesion FIGURE 10.7 Multiple blastic metastases from thyroid carcinoma on CT Radiographs and bone scan were normal CT may show the extent of bone involvement more clearly than radiographs (Fig 10.7) Delineation of the extent of cortical involvement is important when prophylactic internal fixation is contemplated In addition, CT may show tumor in the marrow spaces in the absence of bone destruction Increased attenuation in the medullary cavity reflects replacement of the fatty marrow by tumor, edema, or reactive mesenchymal tissue (Fig 10.8) On MRI, metastatic lesions are seen as focal areas of abnormal signal replacing the normal marrow signal (Fig 10.9) Metastases are usually distinguishable from normal tissue unless the metastases are so extensive that normal marrow signal is absent On T1-weighted images, metastatic foci have low signal intensity; on T2-weighted images, they have high signal intensity; following intravenous gadolinium, they enhance Opposed phase MR sequences can be used to assess for obliteration of the normal marrow fat which is typically seen with tumors When fat and water are present in the same voxel, such as with red bone marrow, then signal dropout will be seen on the out-of-phase image compared with the in-phase image Metastases obliterate the marrow fat, thus having roughly the same signal intensity between in-phase and out-of-phase images (Fig 10.10) MRI is more sensitive than bone scan and has superior anatomic detail Whole-body MRI has been used for detection of bone metastases in children and young adults, using spin echo T1-weighted and inversion recovery sequences MRI is the best examination for investigating acute spinal cord symptoms in patients with known metastatic disease and for screening the spine when the bone scan is negative and profound osteopenia is present (Fig 10.11) MRI may also be particularly helpful in making decisions about staging and treatment when a solitary lesion is found on a screening bone scan and radiographs are normal Metastases may appear in any transverse or longitudinal location within an involved bone, including marrow space, cortex, or surface, and epiphysis, metaphysis, or diaphysis Intracortical or subperiosteal locations are common for metastases (Fig 10.12) but rare for primary bone tumors FIGURE 10.9 Metastases to the lumbar spine, pelvis, and femurs from breast carcinoma A, B: Coronal T1-weighted and inversion recovery MRI shows scattered, focal lesions in the marrow Chew_Chap10.indd 185 1/18/2010 10:58:31 AM 186 Part II • Tumors FIGURE 10.10 Metastasis from lung carcinoma on axial T1-weighted fast spoiled gradient dual echo MRI A: In-phase image shows a rounded lesion in the left sacrum (arrow) and heterogenous marrow in the right ilium (arrowhead) B: Opposed phase image demonstrates lack of signal dropout of the metastasis (arrow) from lack of residual marrow fat and normal signal dropout of the red marrow in the right ilium (arrowhead) Purely fatty replaced marrow in the left hemipelvis is due to prior radiation and does not drop out due to lack of interspersed cellular marrow elements FIGURE 10.11 Widespread spine metastases from breast carcinoma A: Lateral radiograph shows osteopenia and compression fractures in the thoracic spine B: Sagittal T2-weighted MRI shows widespread replacement of the normal marrow signal by high signal lesions Chew_Chap10.indd 186 1/18/2010 10:58:32 AM Chapter 10 • Metastatic Tumors 187 FIGURE 10.12 Cortical metastasis A: CT shows destructive lesion in the posterior cortex of the femur with irregular periosteal reaction (arrow) B: Axial T2-weighted MRI shows the lesion (arrow) with surrounding edema In young children, skeletal metastases tend to be widespread and generally symmetric in their involvement of the skeleton (Fig 10.13) Osteolysis and permeated destruction are prominent, and collapse of vertebral bodies is frequent SCREENING FOR METASTASES FIGURE 10.13 Child with metastases from neuroblastoma The bones are diffusely abnormal with loss of the normal trabecular pattern and cortical edges Chew_Chap10.indd 187 Screening for skeletal metastases in patients with known primary malignancies is usually accomplished with bone scanning; 30% of metastatic lesions detected by bone scan are missed by radiographs, and 2% of metastatic lesions detected by radiographs are missed by scans Because most patients have multiple lesions, it is rare for a patient with osseous metastases to have an entirely normal bone scan The bone scan can be falsely negative or nondiagnostic in debilitated patients with a poor host response or in patients who have had radiotherapy When bone metastases are known to be present, response to therapy can be documented by serial bone scans With successful treatment, lesions with increased isotope uptake tend to become normal, and the number of lesions decreases Sometimes, in the presence of clinical improvement, an increase in lesion intensity is seen after therapy This “flare phenomenon” presumably corresponds to healing of metastatic lesions with increasing formation of the reactive bone Follow-up scans in to months clarify the situation by showing the expected decrease in activity Growth of lesions and the onset of new lesions indicate worsening of the disease When additional lesions are suspected in specific areas of new, worsening, or recurrent pain, plain radiographs are usually obtained first If these are negative, depending on the circumstances, further imaging evaluation may include 1/18/2010 10:58:33 AM 188 Part II • Tumors FIGURE 10.14 Metastasis from colon carcinoma not evident on radiographs A: Composite sagittal T1-weighted and inversion recovery MRI shows replacement of the marrow at L3 (arrows) with low T1 signal and increased signal on fluid sensitive sequence B: Anterior bone scan demonstrates vague increased tracer uptake in L3 (arrow) C: CT prior to biopsy demonstrates subtle sclerosis of the vertebral body bone scan, CT, PET/CT, or MRI, or some combination of these (Fig 10.14) In patients with known primary malignancies and focal symptoms, it is reasonable to obtain radiographs as an initial screening examination for metastatic disease Some treatment protocols may be based on the burden of disease as shown by radiographic osseous survey, despite the greater sensitivity and specificity of other imaging modalities Chew_Chap10.indd 188 HEMATOLOGIC MALIGNANCIES INVOLVING THE BONE SECONDARILY Marrow element malignancies tend to infiltrate and involve the skeleton diffusely and not have the discrete multifocal tumor deposits more typical of metastases from primary tumors of parenchymal organs Primary marrow element tumors (multiple myeloma, Ewing sarcoma, primitive neuroectodermal tumor, and primary lymphoma of the bone) are discussed in Chapter 1/18/2010 10:58:34 AM Chapter 10 • Metastatic Tumors FIGURE 10.15 Child with leukemia Transverse metaphyseal lucencies (arrows) are present, corresponding to marrow space packing with leukemic infiltrates Leukemia Leukemia is a neoplasm of leukocytes that may involve bone secondarily Leukemia is the most common malignancy in children Leukemic infiltration of many organs and tissues, including the marrow spaces, is present and may have a diffuse or nodular character Packing of the marrow spaces with leukemic cells causes 189 FIGURE 10.16 Child with leukemia Diffuse periosteal reaction (arrows) and metaphyseal lucencies are present pressure atrophy of cancellous trabeculae and is seen radiographically as diffuse osteopenia In children, lucent metaphyseal bands may occur, reflecting zones of trabeculae that are thinner and sparser than normal in areas of rapid bone growth (Fig 10.15) Although often seen in children with leukemia, these lucent metaphyseal bands are nonspecific and simply reflect the presence of systemic FIGURE 10.17 Acute lymphoblastic leukemia in a young child A: Coronal T1-weighted MRI (left) shows replacement of the marrow; coronal T2-weighted fat-suppressed MRI (center) shows high signal throughout the marrow spaces; and coronal T1-weighted fat-suppressed MRI following gadolinium injection (right) shows diffuse enhancement B: Axial T2-weighted MRI through the leg shows periosteal reaction (arrow) and surrounding edema Chew_Chap10.indd 189 1/18/2010 10:58:35 AM 190 Part II • Tumors disease or even normal variation Nodular collections of leukemic cells cause focal areas of medullary, cortical, or subperiosteal bone destruction Leukemic infiltration can extend through the cortex by way of the haversian systems, enlarging them by eroding the bone This causes the cortex to appear fuzzy and osteopenic, often with lucent streaks Infiltration of subperiosteal spaces lifts the periosteum and stimulates bone formation (Fig 10.16) Periosteal bone formation that occurs as the periosteum is being lifted results in perpendicular sunburst bone spicules as the periosteum leaves a trail of reactive bone behind Even if radiographs of the bone are normal, widespread marrow space involvement is the rule and can be confirmed by MRI bone marrow aspiration On MRI, leukemia is evident as marrow replacement and periosteal reaction (Fig 10.17) Hodgkin Lymphoma Hodgkin Lymphoma is a malignant tumor of lymph nodes Secondary bone involvement is detected clinically in 5% to 21% of patients, but a much higher incidence can be demonstrated by marrow biopsy or at autopsy Bone involvement usually occurs by direct extension from tumor-filled nodes so that the lumbar spine is affected most commonly Pressure erosion of the cortical surface by enlarged periaortic nodes, without actual invasion, causes scalloping of the anterior aspects of the vertebral bodies Hematogenous spread may occur as well Extensive osteoblastic reaction is usual, but lytic and mixed lesions may occur Ill-defined permeating lesions reflect spread of tumor through the medullary spaces and haversian systems Partial collapse of involved vertebral bodies is possible, representing pathologic compression fractures A densely sclerotic vertebral body, a so-called ivory vertebra, is a classic radiographic sign with the differential diagnosis of lymphoma, blastic metastasis, Paget disease, and, rarely, myelosclerosis, fluorosis, or osteopetrosis FIGURE 10.18 Pathologic fracture (arrows) transversely through lytic metastasis in the humeral shaft stresses of loading, impeding the normal biomechanical dispersion of force Weakening is gradual as cortical bone is infiltrated, eroded, and destroyed Blastic lesions also destroy the cortex, and the reactive bone and stromal bone that give blastic lesions their radiodensity are structurally unsound The bone may fracture under the stresses of normal activity Cortical weakening makes the bone most vulnerable to tensile forces; therefore, in the long bones, pathologic Non-Hodgkin Lymphoma Bone involvement is seen in 5% to 15% of patients with nonHodgkin (extranodal) lymphoma The prevalence of bone marrow involvement in autopsy series is much higher The radiographic appearance of secondary involvement of the bone by lymphoma is identical to that of primary involvement (see Chapter 8) PATHOLOGIC FRACTURE Pathologic fractures through bones involved by metastases are common The most common sites of pathologic fracture are the vertebral bodies, ribs, pelvis, proximal femur, and proximal humerus (Figs 10.18 and 10.19) Metastases of lytic, blastic, and mixed radiographic appearance all cause weakening of the bone In the spine, compression fractures with vertebral collapse occur, presumably as a result of gradual destruction of the trabeculae that bear the compressive loads Involvement of the posterior elements may render some vertebral fractures unstable An epidural mass may be present and may block the spinal canal MRI or myelography with CT can demonstrate the epidural mass, indicate the status of the spinal cord, and delineate the extent of vertebral disease In the long bones, destructive lesions with full-thickness cortical penetration lead to pathologic fractures Gaps in the cortex weaken the bone by causing uneven and aberrant distribution of the Chew_Chap10.indd 190 FIGURE 10.19 Prostate carcinoma with pathologic avulsion fracture of lesser trochanter (long arrow) Brachytherapy seeds (short arrow) are present in the prostate 1/18/2010 10:58:36 AM Chapter 10 • Metastatic Tumors fractures are usually transverse The onset of pain at a site of metastatic involvement may indicate the presence of microfractures in a weakened cortex The goal of treatment of osseous metastases is to palliate pain and prevent pathologic fracture; curative resection is generally not realistic Prophylactic internal fixation of metastatically involved bone is often considered The clinical decision revolves around the patient’s concerns and level of activity, the localization and multiplicity of bone involvement, and the extent of destruction Fixation is generally indicated for lytic lesions if they are greater than 2.5 cm in size or involve more than half the circumference of the bone Pathologic fractures are usually treated surgically Prosthetic replacements allow the removal of the tumor-destroyed bone Methyl methacrylate is often used to buttress destroyed portions of the bone and fill in bony defects Radiotherapy can interfere with secondary healing by destroying chondrogenesis The primary osteogenesis that occurs with internal fixation is more resistant to radiation, so that radiotherapy generally does not interfere with healing of internally fixed fractures If the patient’s life span is long enough, pathologic fractures will heal, but the healing process may be prolonged Median survival after discovery of a pathologic fracture through an osseous metastasis, combined for all primary sites, is approximately 18 months SOFT-TISSUE METASTASES Although the skeletal muscle mass of the human body accounts for a large percentage of the total body weight, nearly 50%, in clinical experience, skeletal muscle is an uncommon site for metastases Muscle is resistant to both primary and metastatic cancers The cited factors for this resistance include contractile activity, local changes in pH, oxygenation, accumulation of lactic acid and other metabolites, blood flow per unit weight (mL/min/g), intramuscular blood pressure, and local temperature Weiss experimentally showed that cancer cell survival is greatest in denervated muscle that is unable to contract as opposed to electrically stimulated muscle His experimental work supports the hypothesis that the rapid death of most cancer cells after delivery to some target organs is a consequence of their mechanical interactions within the microvasculature Muscle metastases have been reported in sites of previously documented skeletal muscle trauma 191 FIGURE 10.20 Soft-tissue metastasis from lung cancer Contrastenhanced CT scan shows a rim-enhanced soft-tissue metastasis (arrow) Autopsies in two series of patients showed that the prevalence of metastases to muscle was 16.0% and 17.5% Neoplasms with the highest incidence of metastases to muscle were carcinoma, leukemia, and lymphoma The diaphragm, rectus muscle of the abdomen, deltoid muscle, psoas muscle, and intercostal muscles were most commonly involved Patients with muscle metastases were 26 to 84 years old (mean age, 62 years old) Most patients present with pain in the involved muscles or a clinically palpable mass and have advanced-stage neoplasms On unenhanced CT scans, muscle metastasis is revealed as an enlargement of a muscle Occasionally, the findings may be subtle because the tumor is isodense to the surrounding muscle, and contralateral asymmetry is necessary to make the diagnosis On contrast enhanced CT, skeletal muscle metastases appear as rimenhancing intramuscular lesions with central hypoattenuation (Fig 10.20) On MRI, muscle metastases have high signal intensity on STIR or T2-weighted sequences, lobulated morphology, large areas of central necrosis, and extensive peritumoral edema (Fig 10.21) MRI findings of carcinoma metastatic to muscle are FIGURE 10.21 Metastases to muscle from lung cancer A: Axial T2-weighted fat-suppressed MRI shows high signal (arrow) in the lateral compartment muscles of the leg B: Axial T1-weighted fat-suppressed MRI following gadolinium injection shows moderate enhancement (arrow) in the lesion Chew_Chap10.indd 191 1/18/2010 10:58:37 AM 192 Part II • Tumors RADIOTHERAPY CHANGES FIGURE 10.22 Insufficiency fractures (arrows) of the right ilium and right sacral wing shown by coronal CT reformation in a patient with previous pelvic irradiation for cervical cancer Note the straight, vertical margins (small arrows) of the bilateral iliac sclerosis, demarcating the margins of the radiation port not pathognomonic, and the differential diagnosis must include soft-tissue sarcoma, hematoma, and abscess Metastases to skin, subcutaneous tissues, and lymph nodes may present as soft-tissue masses On CT, such lesions tend to be isodense to muscle and may enhance Soft-tissue metastases typically have low signal on T1-weighted MRI, high signal on T2-weighted MRI, and enhancement after gadolinium injection Therapeutic irradiation is a common means of treating osseous metastases Sites of bone pain confirmed as abnormal by roentgenography or bone scan in patients with known metastases are often treated palliatively by radiation Irradiated osseous lesions heal by sclerosis and filling-in of lytic areas Radiation effects are independent of the radiation source In the immature skeleton, radiation in total doses of 2,000 cGy or greater impairs the bone growth The epiphysis is especially sensitive; radiation causes direct cellular injury to chondrocytes and possibly vascular damage to fine physeal blood vessels The greater the growth potential at the time of irradiation, the more profound is its effect If an entire growing bone is irradiated, loss of bone growth in the whole bone results in a small bone Focal doses affect the irradiated portion; for example, angular deformities could result from an asymmetrically irradiated growth plate Radiotherapy also increases the risk for epiphyseal plate trauma, including the occurrence of slipped capital femoral epiphysis and avascular necrosis In the mature skeleton, the primary change is radiation necrosis, a phenomenon that is dose related Radiographs and CT show irregular sclerosis in the irradiated bone Insufficiency fracture is a relatively common complication of radiation necrosis (Fig 10.22) On bone scan, the irradiated bone may initially show increased radionuclide accumulation from hyperemia and new bone formation PERCUTANEOUS NEEDLE BIOPSY In the evaluation of a patient with one or more focal lesions in the setting of a known primary tumor or no known primary tumor, percutaneous needle biopsy is often the invasive procedure of choice Typically performed under CT or sonographic guidance, the diagnostic yield is high, and the morbidity is low Virtually any anatomic site may be accessible to needle biopsy, and some sites that would be problematic for the surgeon are straightforward for the interventional bone radiologist A variety of specialized needles are available for obtaining core specimens of the bone or soft-tissue lesions An extraosseous component of a malignant bone tumor is as representative of the tumor as is the bone tumor itself A frozen section of a core biopsy or cytologic preparation of a fine-needle aspiration may provide an immediate pathologic diagnosis Specific benign diagnoses that may account for clinical symptoms or radiologic abnormalities may be made from needle biopsy specimens by the experienced pathologist Aspiration of bone marrow from the iliac crest in many patients may find tumor cells, but these correspond to circulating tumor cells that have been shed into the bloodstream They not necessarily become established skeletal metastases Aspiration specimens may also be sent for bacteriology TREATMENT The basic treatment modalities for osseous metastases, with or without pathologic fractures, are radiation therapy, chemotherapy, and surgical stabilization Palliative radiation of symptomatic lesions without pathologic fracture provides pain relief in approximately 80% of patients If a pathologic fracture is present, pain relief may be experienced by approximately 60% of patients; without internal fixation, the pathologic fractures may progress to nonunion Chew_Chap10.indd 192 FIGURE 10.23 Radiation changes in the marrow on sagittal T1-weighted MRI Fatty replaced bone marrow in L2 and L4 (arrowheads) denotes the radiation portal surrounding a lung carcinoma metastasis (arrow) at L3 The remainder of the levels have normal marrow signal 1/18/2010 10:58:38 AM Chapter 10 • Metastatic Tumors 193 FIGURE 10.24 Radiation changes in muscle months after treatment A: Axial T1 MRI shows previous resection of soft-tissue sarcoma from the lateral portion of the anterior compartment (arrow) B: Axial inversion recovery MRI shows high signal in the lateral thigh soft tissues, including muscle and subcutaneous tissues, with a linear demarcation (arrows) that corresponds to the radiation portal C: Axial T1 fat-suppressed MRI following gadolinium contrast injection shows enhancement (arrows) of the affected soft tissues After several weeks or months, the bone scan shows decreased radionuclide accumulation because of decreased bone formation and decreased vascularity On MRI, the irradiated bone has the signal characteristics of fatty marrow The anatomic location and extent of these changes conform to the size and shape of the radiation portal (Fig 10.23) In patients who received radiotherapy before years of age, induced tumors are usually benign The most common are exostoses (osteochondromas); these are histologically and biologically indistinguishable from those that occur naturally Fibrosarcoma or malignant fibrous histiocytoma, chondrosarcoma, and other unusual sarcomas are much less likely to occur Malignant tumors may occur in older patients who have received radiotherapy The following criteria must be satisfied to make the diagnosis of a radiation-induced sarcoma: (a) the sarcoma arises within the irradiated field, (b) the latent period is at least years, and (c) the sarcoma is histologically different from a previous tumor or the radiation was delivered in the absence of a malignant diagnosis The latent period averages 11 years The presence of pain, soft-tissue mass, and progression on serial films should raise suspicion and lead to biopsy Radiation myositis may occur following external beam radiation and is manifested on MRI as muscle edema and inflammation that peaks several months after treatment (Fig 10.24) The margins of the abnormality will correspond to the radiation field and may extend straight across different muscle groups and other soft tissues Atrophy and volume loss are late effects of radiation myositis SOURCES AND READINGS Berger FH, Verstraete KL, Gooding CA, et al MR imaging of musculoskeletal neoplasm Magn Reson Imaging Clin North Am 2000;8:929–951 Bui-Mansfield LT, Chew FS, Lenchik L, et al Nontraumatic avulsions of the pelvis AJR 2001;178:423–427 Chew_Chap10.indd 193 Damron TA, Heiner J Management of metastatic disease to soft tissue Orthop Clin North Am 2000;31:661–673 eMedicine http://emedicine.medscape.com Fogelman I, Cook G, Israel O, Van der Wall H Positron emission tomography and bone metastases Semin Nucl Med 2005;35(2):135–142 Galasko CSB Skeletal Metastases London: Butterworths; 1986 Glockner JF, White LM, Sundaram M, et al Unsuspected metastases presenting as solitary soft tissue lesions: A fourteen-year review Skeletal Radiol 2000;29:270–274 Herring CL, Harrelson JM, Scully SP Metastatic carcinoma to skeletal muscle—a report of 15 patients Clin Orthop 1998;355:272–281 Hudson TM Radiologic-Pathologic Correlation of Musculoskeletal Lesions Baltimore, MD: Williams & Wilkins; 1987:421–440 Kagan AR, Bassett LW, Steckel RJ, et al Radiologic contributions to cancer management Bone metastases AJR 1986;147:305–312 Lipton A Future treatment of bone metastases Clin Cancer Res 2006 Oct 15;12(20 Pt 2):6305s–6308s Magee T, Rosenthal H Skeletal muscle metastases at sites of documented trauma AJR 2002;178:985–988 Mollabashy A, Scarborough M The mechanism of metastasis Orthop Clin North Am 2000;31:529– 535 Orr FW, Lee J, Duivenvoorden WC, et al Pathophysiologic interactions in skeletal metastasis Cancer 2000;88(Suppl.):2912–2918 Panicek DM, Schwartz LH MR imaging after surgery for musculoskeletal neoplasm Semin Musculoskelet Radiol 2002;6:57–66 Plaza JA, Perez-Montiel D, Mayerson J, et al Metastases to soft tissue: A review of 118 cases over a 30-year period Cancer 2008; 112:193–203 Resnick D Diagnosis of Bone and Joint Disorders 4th Ed Philadelphia, PA: WB Saunders; 2002 Taira AV, Herfkens RJ, Gambhir SS, Quon A Detection of bone metastases: Assessment of integrated FDG PET/CT imaging Radiology 2007; 243(1):204–211 Virk MS, Lieberman JR Tumor metastasis to bone Arthritis Res Ther 2007;9(Suppl 1):S5 1/18/2010 10:58:39 AM Chew_Chap10.indd 194 1/18/2010 10:58:39 AM ... Postsurgical Imaging 315 335 ix Chew_FM.indd ix 1/ 21/ 2 010 12 :37 :11 PM Chew_FM.indd x 1/ 21/ 2 010 12 :37 :11 PM PA RT I Trauma Chew_Chap 01. indd 1/ 19/2 010 8:00:28 AM CHAPTER Approach to... FIGURES 17 .28 17 . 51: Used with permission from the following sources: Chew FS Skeletal Radiology: The Bare Bones Rockville, MD: Aspen Publishers; 19 89; Chew FS Skeletal Radiology: The Bare Bones. .. Osteomyelitis AJR 19 94 ;16 2:942 FIGURE 17 .27 A, B: From Chew FS, Ramsdell MG, Keel SB Metallosis after total knee replacement AJR 19 98 ;17 0 :15 56 FIGURES 1. 1–8.26, FIGURES 8.28 15 . 41, FIGURES 16 .2 17 .26, and